1. Field of the Invention
The present invention relates to a liquid crystal composition and a liquid crystal display (“LCD”) apparatus having the liquid crystal composition. More particularly, the present invention relates to a liquid crystal composition used for an LCD apparatus and an LCD apparatus having the liquid crystal composition.
2. Description of the Related Art
A liquid crystal display (LCD) apparatus includes an LCD panel and a backlight assembly supplying the LCD panel with light. The LCD panel includes a first substrate, a second substrate and a liquid crystal layer. The first substrate generally includes gate lines, data lines, switching elements and pixel electrodes, formed on a surface of the first substrate. The second substrate is located opposite the first substrate and includes common electrodes. The liquid crystal layer is interposed between the opposing surfaces of the first and the second substrates so that corresponding electrical and optical contacts on each opposing surface are disposed to coincide.
When an electrical field is induced (i.e., formed) between the pixel electrodes and the common electrodes, the liquid crystal molecules of the liquid crystal layer orient so that their axes align in the same direction and with the same degree of rotation according to the strength of the field, and in this way the liquid crystal molecules in the electrical field collectively act as a variable shutter to control the transmittance of light. Accordingly, the LCD apparatus displays images.
A vertical alignment (“VA”) mode, which is a type of display mode, has been developed in order to improve viewing angles. Generally, liquid crystal molecules in the VA mode have a negative dielectric anisotropy.
After the LCD display apparatus displays one image, the LCD apparatus then displays another image. This second, residual image may be displayed when the other image is displayed. The other image having the residual image is referred to as an afterimage. The afterimage may be caused by impurities entering the liquid crystal layer, and when the response time of the liquid crystal molecules is slow. Due to the afterimage, the LCD apparatus may have reduced display quality.
For example, afterimage problems may be resolved by improving the rising time and/or falling time of the liquid crystal molecules, thereby improving the response time.
However, molecules that are added to a liquid crystal composition in order to improve the response time may actually increase afterimages and reduce the reliability of the LCD apparatus.